Rack & Pinion
R&P steering should be fine on your truck. Providing you can find one that has the same pivot points as the inside bushing on the lower control arm at dead center.
If not, then you'll end up with "bump steer" and that is a NO NO. It also should remain parallel with the center line of the axle stubs or close to it for the same reason.
Study and measure the pivots on the center link on the existing steering, then study and measure those on given R&P's. Find one that measures the same and you should be ok.
Just dont' take one from a Chevette size car or import.